20.1.6.1 Setting Options

Options control things like the color and border width of a widget.
Options can be set in three ways:

At object creation time, using keyword arguments

:

fred = Button(self, fg = "red", bg = "blue")

After object creation, treating the option name like a dictionary index

:

fred["fg"] = "red"
fred["bg"] = "blue"

Use the config() method to update multiple attrs subsequent to
object creation

:

fred.config(fg = "red", bg = "blue")

For a complete explanation of a given option and its behavior, see the
Tk man pages for the widget in question.

Note that the man pages list "STANDARD OPTIONS" and "WIDGET SPECIFIC
OPTIONS" for each widget. The former is a list of options that are
common to many widgets, the latter are the options that are
idiosyncratic to that particular widget. The Standard Options are
documented on the options(3) man page.

No distinction between standard and widget-specific options is made in
this document. Some options don't apply to some kinds of widgets.
Whether a given widget responds to a particular option depends on the
class of the widget; buttons have a command option, labels do not.

The options supported by a given widget are listed in that widget's
man page, or can be queried at runtime by calling the
config() method without arguments, or by calling the
keys() method on that widget. The return value of these
calls is a dictionary whose key is the name of the option as a string
(for example, 'relief') and whose values are 5-tuples.

Some options, like bg are synonyms for common options with long
names (bg is shorthand for "background"). Passing the
config() method the name of a shorthand option will return a
2-tuple, not 5-tuple. The 2-tuple passed back will contain the name of
the synonym and the ``real'' option (such as ('bg',
'background')).